454 sequencing (pyrosequencing)

Definition

454 sequencing, also known as pyrosequencing, is a method of DNA sequencing that relies on the detection of pyrophosphate release during nucleotide incorporation. It allows for the rapid sequencing of short to medium-length DNA strands.

5 Must Know Facts For Your Next Test

1. 454 sequencing uses a 'sequencing by synthesis' approach where nucleotides are added one at a time and detected by light emission.
2. The technology involves four key enzymes: DNA polymerase, ATP sulfurylase, luciferase, and apyrase.
3. It was one of the first next-generation sequencing (NGS) technologies to be commercialized.
4. Pyrosequencing can accurately sequence homopolymeric regions up to around 8-10 bases long but struggles with longer homopolymers.
5. This method generates reads that are typically shorter than those produced by newer NGS methods like Illumina sequencing.

Review Questions

Related terms

Next-Generation Sequencing (NGS): A category of high-throughput DNA sequencing technologies that have revolutionized genomic research.

Illumina Sequencing: A widely used NGS technology that utilizes reversible dye terminators for detecting nucleotide incorporation.

Sequencing by Synthesis: A method where nucleotides are incorporated into a growing DNA strand and detected in real-time.